Guitar Center has made available MP3 files of all of the backing tracks. There are 30 tracks of various blues styles --Chicago blues, Texas blues, Slow Blues, Swing, Shuffle, T-Bone Walker style, you name it. Although the key is not always indicated, they are mostly in A, D, E or are otherwise easy to figure out. For the new songs there are charts that give all the chords.
Check out the new backing tracks featured in the video for some great blues inspiration!